The present invention generally relates to a bearing and more particularly, to an improved tapered roller bearing.
Conventionally, a tapered roller bearing is formed with a large shoulder at a large diameter portion of an inner race, and a small shoulder at a small diameter portion thereof respectively. The large shoulder receives an axial thrust load acting on the bearing during rotation for guiding the rotation of the tapered rollers. On the contrary, although not particularly necessary for the function of the bearing during rotation thereof, the small shoulder is essential to prevent respective parts from separation after the inner race, tapered rollers and a cage have been assembled with each other, and has for its object to obstruct the axial movement of the tapered rollers after the assembling.
However, formation of such a small shoulder complicates the processing of the inner race, with a simultaneous reduction of the material yield, while, due to the fact that the length of the small shoulder is added to that of the inner race, the tapered roller bearing is undesirably increased in its size in the axial direction thereof, with a consequent increase in its weight also.
Incidentally, bearings are widely employed as basic parts for various mechanical arrangements, but, owing to the recent requirements for compact size and light weight of bearings, it has now became rather difficult to fully meet the purpose by the conventional bearings as described above.